RETRACTOR FOR MINIMALLY INVASIVE SURGERY

Abstract

A surgical retractor comprises an elongate member having a coupling region disposed at one end thereof. The retractor is adapted to engage a base of a head of a pedicle screw. The coupling region of the elongate member has a filament-receiving hole adapted to receive a filament which captures the head of the pedicle screw. During surgery, a physician may retract muscle and soft tissue by simply pressing the elongate member against such tissue.

Description

Claims priority to U.S. provisional appl. No. 60/978,147 filed 8 Oct. 2007.

This invention relates to surgical retractors and in particular, surgical retractors which retract muscle and soft tissue from an operative site during spinal surgery and the installation of spinal prosthesis.

Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention.

US Patent Application Publication US 2007/0106123A1, to Gorek et al, filed Sep. 26, 2006, the content of which arc incorporated herein by reference thereto and relied upon, describes such a retractor. Although suitable for minimally invasive surgery, the Gorek device suffers from the need for special tools to remove the retractor elongate members or blades 8.

BACKGROUND OF THE INVENTION

What is needed is a retractor and method suitable for minimally invasive surgery which does not require special tools and which is otherwise easy to remove after it's purposes are served.

SUMMARY OF THE INVENTION

The retractor assembly of the invention includes an elongate member, a pedicle screw, and a filament. The elongate member has a coupling region disposed at one end thereof. The retractor assembly is adapted to engage a base of a head of the pedicle screw. The coupling region of the elongate member has a filament-receiving hole adapted to receive the filament which captures the head of the pedicle screw, following a path or alternate path to loop around the pedicle screw at the base of the head. The filament has a free end which may be wedged in a filament receiving slit, to fix the free end in place.

An object of the invention is to better enable minimally invasive surgery while providing a simple means to remove the retractors, by simply removing the free ends of the wire from their retainer and pulling them through the filament receiving recesses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is an exploded view of the retractor assembly of the invention.

FIG. 1b is an exploded view of another embodiment of the retractor assembly of the invention.

FIG. 2 is a perspective view of the retractor assembly of the invention.

FIG. 3 is a perspective view of the retractor assembly of the invention, retracted to push back tissue from the operative site.

FIG. 4a is a side view of a pedicle screw for use with the retractor assembly of the invention.

FIG. 4b is a cross sectional view of the pedicle screw taken along plane A-A of FIG. 4a.

FIG. 4c is a cross sectional view of the pedicle screw taken along plane B-B of FIG. 4b.

FIG. 4d is a rear view of the pedicle screw for use with the retractor assembly of the invention.

FIG. 4e is a perspective view of the pedicle screw for use with the retractor assembly of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1a, the retractor assembly 10 of the invention includes an elongate member 12, a pedicle screw 14 and a filament 16. The elongate member 12 has a coupling region 20 disposed at one end thereof. The retractor assembly 10 is adapted to engage a base 22 of a head 24 of the pedicle screw 14. The coupling region 20 of the elongate member 12 has a filament-receiving hole 26 adapted to receive the filament 16 which captures the head 24 of the pedicle screw 14, following a path 30 or alternate path 31 to loop around the pedicle screw 14 at the base 22 of the head 24. The filament 1.6 has a free end 32 which may be wedged in a filament receiving slit 34, to fix the free end in place.

The elongate member 12 may be made of a polymer, as also the filament 16.

Referring now to FIG. 1b, in an alternate embodiment, a retractor assembly 10′ includes two elongate members 12 and filaments 16 which pass through filament receiving holes 26 or recesses 26′ (see FIG. 4a) at the base 22 of the head 24 of the pedicle screw 14. Alternatively, the filaments 16 may simply loop around the base 22 of the head 24 as shown in FIG. 1a.

During surgery, a physician may retract muscle and soft tissue by simply pressing the elongate member against such tissue. Further, to remove the assembly, all that is required, is that the filament ends 32 be removed from their holders and the filaments pulled out of the assembly. No special tools are therefore required for removal after installation of the pedicle screw 14 and rod (not shown) which interfaces with the pedicle screw.

Referring flow to FIG. 2, the retractor assembly 10′ of the invention is shown in a non-extended, assembled position. To retract tissue, a distal end 12′ of an elongate member 12 must be moved away (see FIG. 3) from the axis 36 of the assembly 10′, and so, like a tongue depressor, it moves tissue out of the way so a surgeon can gain functional access to the operative site.

A method of performing spine surgery using the invention 10, 10′, includes the following steps. In a first step 50, at least two retractor assemblies 10, 10′, are provided to the surgical site, each retractor assembly including at least one elongate member attached to a coupling region of the retractor wherein filaments passing through the retractor assemblies and around the base of the head of the pedicle screw retain the retractor assemblies about the screw. In a second step 52, a first screw is secured to a portion of a first vertebral body. In a third step 54, tissue is retracted using the at least one elongate member of the first retractor. In a fourth step 56, a second screw is secured to a portion of a second vertebral body. In a fifth step 60, tissue is retracted using the at least one elongate member of the second retractor. In a sixth step 62, a rod is inserted between the first and second screws. In a seventh step 64, the rod is secured to the first and second screws. In an eighth step 66, the first and second retractors are removed by removing the filament 16 in a conventional manner such as by cutting.

In an advantage, the assembly 10, 10′ enables minimally invasive surgery while providing a simple means to remove the retractors, by simply removing the free ends 32 of the wire from their retainer 34 and pulling them through the filament receiving recesses 26, 26′.

The patents and articles mentioned above are hereby incorporated by reference herein, unless otherwise noted, to the extent that the same are not inconsistent with this disclosure.

Other characteristics and modes of execution of the invention are described in the appended claims.

Further, the invention should be considered as comprising all possible combinations of every feature described in the instant specification, appended claims, and/or drawing figures which may be considered new, inventive and industrially applicable.

Multiple variations and modifications are possible in the embodiments of the invention described here. Although certain illustrative embodiments of the invention have been shown and described here, a wide range of modifications, changes, and substitutions is contemplated in the foregoing disclosure. While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another preferred embodiment thereof. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the foregoing description be construed broadly and understood as being given by way of illustration and example only, the spirit and scope of the invention being limited only by the claims which ultimately issue in this application.

Claims

1. A surgical retractor comprising: at least one elongate member; a coupling region disposed at one end of the surgical retractor adapted to engage a base of a head of a pedicle screw, the coupling region having at least one filament-receiving hole adapted to receive a filament which captures the head of the pedicle screw.

2. The surgical retractor of claim 1, wherein a guide wire is looped through the hole so as to cinch around the base of the head of the pedicle screw.

3. The surgical retractor of claims 1 or 2, wherein the elongate member, distal to the coupling region, has at least one wire lock slit adapted to receive the ends of the wire and fix them in place.

4. The surgical retractor of claim 1, wherein the elongate member has at least two filament receiving holes.

5. The surgical retractor of claim 1, wherein the elongate member has at least one filament receiving slit in a distal end of the elongate member, into which a free end of the filament may be locked.

6. The surgical retractor of claim 1, wherein the elongate member is made from a polymer.

7. The surgical retractor of claim 1, further including the filament made from a polymer.

8. The surgical retractor of claim 1, further including the pedicle screw, wherein the pedicle screw has at least one recess for receiving the filament to better fix the retractor about the screw.

9. A method of performing spine surgery comprising the steps of:

a. providing at least two retractor assemblies, each retractor assembly including at least one elongate member attached to a coupling region of the retractor wherein filaments passing through the retractor assemblies and around the base of the head of the pedicle screw retain the retractor assemblies about the screw;

b. securing a first screw to a portion of a first vertebral body;

c. retracting tissue using the at least one elongate member of the first retractor;

d. securing a second screw to a portion of a second vertebral body;

e. retracting tissue using the at least one elongate member of the second retractor;

f. inserting a rod between the first and second screws;

g. securing the rod to the first and second screws: and

h. removing the first and second retractors by removing the filament in a conventional manner such as by cutting.

10. The retractor assembly as described in the instant specification, dependent claims, and/or drawing figures.